Final answer:
The lectin pathway is activated by the binding of an acute-phase protein, such as mannose-binding lectin, to a pathogen. This pathway leads to the activation of the complement system, which assists in the innate immune response through opsonization, inflammation, and lysis of the pathogen.
Step-by-step explanation:
The complement activation pathway that is triggered by the binding of an acute-phase protein to a pathogen is the lectin pathway. This pathway is akin to the classical pathway but is initiated by the binding of a mannose-binding lectin (MBL), which is an acute-phase protein, to the carbohydrate components of pathogens. Upon binding, MBL associates with serine proteases, leading to the activation of the complement system independent of antibodies. The activated complement then promotes opsonization, inflammation, and lysis of the pathogen. The classical pathway requires antibodies already bound to antigens, the alternative pathway is spontaneously activated without antibodies or lectins, and the cathelicidin is a different type of antimicrobial peptide not directly involved in complement activation.